{"paper":{"title":"Observation of the Decay K^+ --> pi^+ gamma gamma","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. J. S. Smith, A. Konaka, A. Sambamurti, A. Stevens, A. S. Turcot, C. Witzig, D. A. Bryman, D. R. Marlow, D. S. Akerib, E787 Collaboration: P. Kitching, E. W. Blackmore, F. C. Shoemaker, I-H. Chiang, J. A. Macdonald, J.-M. Poutissou, J. Roy, J.S. Frank, J.S. Haggerty, K. K. Li, L. Felawka, L. S. Littenberg, M. Ardebili, M. A. Selen, M. Convery, M. M. Ito, M. Rozon, M.S. Atiya, P. D. Meyers, P. Padley, R. A. McPherson, R. C. Strand, R. Poutissou, R. Soluk, S. Adler, T.F. Kycia, T. Nakano, T. Numao, W. C. Louis, Y. Kuno","submitted_at":"1997-08-08T00:07:45Z","abstract_excerpt":"The first observation of the decay K^+ --> pi^+ gamma gamma is reported. A total of 31 events was observed with an estimated background of 5.1 +- 3.3 events in the pi+ momentum range from 100 MeV/c to 180 MeV/c. The corresponding partial branching ratio, B(K+ -> pi+ gamma gamma, 100 MeV/c < P_pi^+ < 180 MeV/c), is (6.0 +- 1.5 (stat) +- 0.7 (sys)) x 10^{-7}. No K^+ --> pi^+ gamma gamma decay was observed in the pi^+ momentum region greater than 215 MeV/c. The observed pi^+ momentum spectrum is compared with the predictions of chiral perturbation theory."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ex/9708011","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/hep-ex/9708011/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}